Analysis of image sticking on a real MVA Cell

Abstract

Abstract— Image‐sticking phenomenon is one of the most important issues affecting LCDs, especially LCD TV. It is known that image sticking is caused by residual DC voltage. An analysis of the cause that induces image sticking on a real LCD cell is very difficult to perform and is rarely reported. In this paper, the impurities that cause boundary image sticking on a real MVA cell was analyzed by examining a cross section of a cell, the bulk LC layer, the vicinity of the LC layer, the LC layer/PI alignment film interface using microanalysis methods such as infrared micro‐spectroscopy (μ‐IR) and micro‐sampling mass spectrometry (μ‐MS). It is clarified that there is quite a bit of aromatic acid at the boundary of the image‐sticking area than in the normal area at the LC/PI alignment film interface on the color‐filter side, not the TFT side, and it is assumed that aromatic carboxylic acid, a negative charged material, is condensed at the LC/PI alignment film interface on the color filter side by an electrically driven DC component inducing an electric‐condenser residual DC voltage.

Relation between Monomer Structure and Image Sticking Phenomenon of Polymer-Sustained-Alignment Liquid Crystal Displays

“…There are many reports that residual DC affects the image sticking of conventional LCDs. [7][8][9][10][11] The generation mechanism of image sticking due to a residual DC is as follows. If a symmetrical square wave is applied to an LC cell with a residual DC, the LC cell appears to flicker because an asymmetric square wave, which is the sum of the externally applied voltage and the residual DC voltage, is applied to the LC layer of the LC cell as shown in Fig.…”

P‐103: Chemical Analysis of Polymerization of Monomer Suspended in PS‐MVA‐LCD

“…Analysis methods and instruments are much important to clarify polymerization and the residual monomer in LCD. The center area on a cell (No.1) and the surrounding area (No.2) for comparison were analyzed dividing a cell cross sectional direction, bulk liquid crystal (LC) layer, vicinity LC layers of both sides and UV incident interface LC layer/polyimide (PI) film TFT side and reversal interface LC layer/polyimide film CF side as like as the same method on IDW and SID reported (Figure1) [2], [3], [4].…”

P‐116: Chemical Analysis of UV‐Cured Polymerization Net‐Work Structure of Monomer Suspended in Blue Phase LCD

“…Analysis methods and instruments are much important to clarify cured polymer and the residual monomer in LCD. The center area on ITO of a cell (No.1) and the surrounding area on glass (No.2) for comparison were analyzed dividing a cell cross sectional direction, bulk liquid crystal (LC) layer, UV incident side interface LC layer/polyimide film (A) and reversal incident side interface LC layer/polyimide film (B) as like as the same method on IDW and SID reported (Figure1) [2], [3].…”